CONTROL OF VARIOUS SULPHUR COMPOUNDS EMISSIONS DURING PYROLYSIS OF MIXTURES OF FOREST AND AGRICULTURAL WASTES. EFFECT OF SULPHUR CONCENTRATION ON DIOXINS FORMATION

摘要

This work aims to study the thermal behaviour of olive pomace (OP), pyrenean oak (PK) and theirblends under pyrolysis using thermogravimetric analysis (TGA). By coupling mass spectrometric analysis (MS) itwas possible to monitorize the emissions released during the process. The OP/PK blends were prepared at fivedifferent ratios and experiments were carried out under non-isothermal conditions in the temperature range 25-750 ℃using Ar as inert gas. Thus, the following species were analysed: a) aromatic compounds (benzene and toluene), b)sulphur emissions (sulphur dioxide) c) chlorine compounds (dichloromethane) d) 1,4-dioxin and e) carbon dioxide.The results obtained indicated that aromatic compounds are released mainly in the temperature range of 275-455 ℃,where the most significant weight loss are observed in the TG curves. It was found that the maximum of the curvescorresponding to these compounds is shifted towards lower values of temperature as the content of OP is increased,which could be related to higher the presence of some inherent minerals in this material (such as potassium). Theintensity of sulphur dioxide and chloromethane emissions were related to the composition (S and Cl proportions) ofthe blends; also the peaks associated to these compounds was shift towards higher temperatures for lower OPcontents in both cases.